The presumptive Democratic nominee still holds a 5-point advantage over the presumptive Republican nominee in CNN's average of national polls, 46 to 41 percent, with 13 percent of voters surveyed undecided. On Tuesday, Obama held the same edge, 48 to 43 percent over McCain, and 9 percent of voters said they were unsure of their choice.

CNN’s Wednesday survey of major national polls consists of the CBS survey conducted July 31 to August 5, the AP-IPSOS poll conducted July 31 to August 4, and the Gallup tracking poll results for August 3-5. The CNN poll of polls does not have a margin of error.

(CNN) - The Democratic presidential race is tightening nationally, according to a new CNN average of several recent polls.

Obama's lead is now down to 1 point over Clinton nationwide, 45 percent to 44 percent, in CNN's "poll of polls." That margin is down 3 points from another CNN poll of polls conducted two days ago. In that analysis, Obama led Clinton 47 percent to 43 percent. The margin is also considerably lower than an April 18 poll of polls that showed Obama with an 11 point lead.

The poll of polls consists of three newly released national polls from Fox News/Opinion Dynamics, Gallup, and Newsweek. There is no margin of error on the poll of polls.

Both the Fox News poll and the Gallup poll were conducted partially after Obama's former pastor, the Rev. Jeremiah Wright, made a fresh round of controversial comments earlier this week.

The Fox News poll also appears to show Obama no longer has an edge over Clinton among independent voters. In head-to-head match ups, presumptive Republican nominee John McCain wins independents by a 4 point margin over Clinton (42-38 percent) and by a 10 points over Obama (47 percent to 37 percent).